First of all, no, it is not covered in the FAQ Common issues (http://forums.winamp.com/showthread.php?t=161361#common
.mp3 files are playing with a low volume. I have played the exact same file in Windows Media Player/Center and have had no issues (but I despise them).
Yes, I have checked my preferences, and checked/unchecked Volume with the Nullsoft WaveOut Output as some have suggested.
No, I am not running any third party plug-ins.
This began occurring roughly 3 days ago, in which time I did not install any new software or hardware. Nor did I change any settings in Winamp prior to tinkering with the output plugin settings trying to resolve the issue.
Yes, I have reinstalled Winamp, with no results.
No, this is not a joke.
Edit: Just checked/tinkered the default windows volume mixer. It did not yield any desired results.